title: Hyperfine interactions and electric dipole moments in the [16.0]1.5(v = 6), [16.0]3.5(v = 7), and X2Δ(5/2) states of iridium monosilicide, IrSi.
abstract: The (6,0)[16.0]1.5-X(2)Δ(5/2) and (7,0)[16.0]3.5-X(2)Δ(5/2) bands of IrSi have been recorded using high-resolution laser-induced fluorescence spectroscopy. The field-free spectra of the (191)IrSi and (193)IrSi isotopologues were modeled to generate a set of fine, magnetic hyperfine, and nuclear quadrupole hyperfine parameters for the X(2)Δ(5/2)(v = 0), [16.0]1.5(v = 6), and [16.0]3.5 (v = 7) states. The observed optical Stark shifts for the (193)IrSi and (191)IrSi isotopologues were analyzed to produce the permanent electric dipole moments, μ(el), of -0.414(6) D and 0.782(6) D for the X(2)Δ(5/2) and [16.0]1.5 (v = 6) states, respectively. Properties of the X(2)Δ(5/2) state computed using relativistic coupled-cluster methods clearly indicate that electron correlation plays an essential role. Specifically, inclusion of correlation changes the sign of the dipole moment and is essential for achieving good accuracy for the nuclear quadrupole coupling parameter eQq0.
authors.affiliation: Department of Chemistry and Biochemistry, Arizona State University , Tempe, Arizona 85287-1604, United States.
authors.forename: Anh
authors.initials: A
authors.lastname: Le
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Steimle
authors.forename: Michael D
authors.initials: MD
authors.lastname: Morse
authors.forename: Maria A
authors.initials: MA
authors.lastname: Garcia
authors.forename: Lan
authors.initials: L
authors.lastname: Cheng
authors.forename: John F
authors.initials: JF
authors.lastname: Stanton